| 1 | /*************************************************************************** |
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| 2 | * blitz/array/convolve.cc One-dimensional convolution |
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| 3 | * |
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| 4 | * Copyright (C) 1997-2001 Todd Veldhuizen <tveldhui@oonumerics.org> |
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| 5 | * |
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| 6 | * This program is free software; you can redistribute it and/or |
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| 7 | * modify it under the terms of the GNU General Public License |
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| 8 | * as published by the Free Software Foundation; either version 2 |
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| 9 | * of the License, or (at your option) any later version. |
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| 10 | * |
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| 11 | * This program is distributed in the hope that it will be useful, |
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| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 14 | * GNU General Public License for more details. |
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| 15 | * |
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| 16 | * Suggestions: blitz-dev@oonumerics.org |
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| 17 | * Bugs: blitz-bugs@oonumerics.org |
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| 18 | * |
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| 19 | * For more information, please see the Blitz++ Home Page: |
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| 20 | * http://oonumerics.org/blitz/ |
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| 21 | * |
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| 22 | ****************************************************************************/ |
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| 23 | |
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| 24 | #ifndef BZ_ARRAY_CONVOLVE_CC |
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| 25 | #define BZ_ARRAY_CONVOLVE_CC |
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| 26 | |
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| 27 | BZ_NAMESPACE(blitz) |
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| 28 | |
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| 29 | template<typename T> |
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| 30 | Array<T,1> convolve(const Array<T,1>& B, const Array<T,1>& C) |
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| 31 | { |
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| 32 | int Bl = B.lbound(0), Bh = B.ubound(0); |
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| 33 | int Cl = C.lbound(0), Ch = C.ubound(0); |
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| 34 | |
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| 35 | int lbound = Bl + Cl; |
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| 36 | int ubound = Bh + Ch; |
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| 37 | |
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| 38 | Array<T,1> A(Range(lbound,ubound)); |
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| 39 | |
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| 40 | for (int i=lbound; i <= ubound; ++i) |
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| 41 | { |
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| 42 | int jl = i - Ch; |
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| 43 | if (jl < Bl) |
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| 44 | jl = Bl; |
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| 45 | |
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| 46 | int jh = i - Cl; |
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| 47 | if (jh > Bh) |
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| 48 | jh = Bh; |
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| 49 | |
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| 50 | T result = 0; |
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| 51 | for (int j=jl; j <= jh; ++j) |
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| 52 | result += B(j) * C(i-j); |
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| 53 | |
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| 54 | A(i) = result; |
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| 55 | } |
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| 56 | |
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| 57 | return A; |
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| 58 | } |
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| 59 | |
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| 60 | BZ_NAMESPACE_END |
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| 61 | |
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| 62 | #endif // BZ_ARRAY_CONVOLVE_CC |
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| 63 | |
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